Everyday toxin study eye-opener

A first-of-its-kind study has given an eye-opening snapshot of what concerning chemicals Kiwis are being exposed to in our everyday environment, finding traces of lead, mercury and several other substances.

While the levels detected among 319 adults and 303 children who took part in the two-year Massey University-led study were broadly in line with those of other developed countries, they did throw up differences in exposure depending on factors like age, gender and location.

Lead and mercury levels were determined in blood samples, while urine samples were analysed for other metals — arsenic, cadmium, chromium, thallium, antimony — cotinine, the main metabolite of nicotine, along with fluoride and phenols.

The Ministry of Health-funded study, which has set New Zealand’s first baseline of exposure to these chemicals, also covered phthalates, which are substances added to plastics and consumer products.

Lead was detected in all of the whole blood samples from 304 adults and 193 children — and levels were highest among children in the Northland and Auckland regions.

None had amounts that were above warning levels, and rates were generally comparable to those from the US and Canada.

For both children and adults, the lowest levels of fluoride were observed in the South Island, likely reflecting regional differences in water fluoridation.

Concentrations of phthalates, commonly used as plasticisers in plastics, were the highest in the youngest age group, age 5 to 7.

Cotinine, analysed from urine samples, was detected among 11 per cent of adults and 2 per cent of children — and only Ma¯ori children.

Project leader Associate Professor Andrea ‘t Mannetje said as the study set a baseline for tracking exposure trends, it could help assess the effectiveness of policies aimed at reducing exposure to environmental chemicals.